Carton construction



Oct. 255 1938. C BLOOMER 2,133,946

CARTON CONSTRUCTION Filed March 23, 1936 2 Sheets-Sheet 1 INVENTOR. fia/TQQ@ ZaaPev' BY zis ATTORNEY.

Oef. 25, 193s. H, C, BLOOMER- 2,133,946

CARTON CONSTRUCTION Filed March 23, 1936 2 sheets-sheet 2 'uxunmulllllumlmm""lllluuumunuumnuuilHHmmmmlllllumnmn A] Parental oa. 25,1938 I UNITED STATES CARTON CONSTRUCTION I Harrison C. Bloomer, Newark, N. Y., assignor to Bloomer Bros. Company, Newark, N. Y., a corporation ot New York Application March 23, 1936, Serial No. 70,295

1l Claims.

to cartons, and particutear-apart or pull-apart This invention relates larly to cartons of the type.

When various products, such, for example, as ice cream, are packed in cartons, it is often'desirable to be able to disassemble the carton in such a manner that it may be laid out flat to obtain free access to the contents so that ice cream, for example, can be removed readily from the carton in the form of a single brick or lump, `instead of having to be dug out of the carton bit by bit. Accordingly, it has been proposed to provide cartons in which one of the adhesive joints may be broken by the application of reasonable force, to enable the carton to be opened out flat, a tab is usually provided which may be grasped and pulled to break the joint.

One disadvantage of this construction is that frequently the force exerted `.,lpon the tab to open the carton is apt to tear the tab portion from the rest of the carton body, or to tear the body back in a strip having a width equal to the Width of the tab portion, instead of breaking the whole adhesive joint and separating the overlapped layers of sheet material from each other as should be done. Such tearing is especially apt to occur where the carton is made of paper or fiber board having a grain running in the same direction as the direction of pull on the tab.

Another disadvantage is that, even when the tab.

does not tear oi or tear back, the breaking of the adhesive joint is apt to cause surface tearing of the sheet material in an objectionable manner.

An object of the presentinvention is to remedy o both of these objections, and particularly to pro- Vide a carton so designed and constructed that the tab will not tear off, or tear back when a force is applied to the tab to open the carton, and that no objectionable surface tearing of the sheet material will take place.

Another object is the provision of an improved carton in which surface tearing of the sheet material, when the carton is opened, is confined to the inner or under layer of the two overlapping layers of sheet material, and in which the possible extent of such tearing is limited by an edge of the sheet material closely adjacent the adhesive zone where the tearing begins.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Fig. 1 is a view of a carton constructed in accordance with one embodiment of the invention, seen at .a preliminary stage of its manufacture; Fig. 2 is a view oi' the same carton completed in knocked-down form; l I

Fig. 3 is a section substan ally on the line 3-3 '5 of Fig. 2; 'l

Fis. 4 is a view similar to Fig. 1 showing a modified-form of construction; v Y

Fig. 5 is a.view similar to Fig. 2 showing the same modified form of construction in the completed knocked down condition;

Fig. 6 is a view similarl to a fragment of Figs. 1 and 4 illustrating a further modification;

Flg. 7 is a view similar to Fig. 6 illustrating still another modification; 1 Fig. 8 is a similar view illustrating another possible modification of the invention;

Fig. 9 is a section substantially on the line 9-9 of Fig. 8, and

Fig. 10 is a view similar to Figs. 6, "I, and 8 20 illustrating a further modification.

'I'he same reference numerals throughout the several views indicate the same parts.

The present invention is independent of the exact form .or shape of the carton. As a cong5 venient example, there is illustrated in the drawings a carton having panels II, I2, I3, and Il, and a ap I5, all made from the same strip or piece of paper or ber board, the panel II being shown folded over the panel I2 in the drawings. 30 When the ap I5 is overlapped with the upper edge of the panel II and secured thereto, as-by adhesive, the panels II, I2, I3, and I4 then form the four sides of the carton and may be erected into a rectangular cross-section, and the ends 35 of the carton may be closed by suitable end aps of known construction.

At I6 there is indicated a tab, placed at any convenient point along the edge of the iiap I5, to be grasped and pulled upwardly or outwardly 40 to separate the overlying viiap layer I5 from the underlying panel layer II, in order to tear the carton open along this joint and thus obtain easier access to the contents of the carton.

Thelayers I I and I5 may be secured to each 45 other by a zone or line of adhesive I'I. InL Fig.

1, this zone or line of adhesive is shown as a continuous strip of ladhesive extending throughout the length of the flap I5, but it is not necessarily in this form. The adhesive may be of any suitable kind, such as'animal or vegetable glue, casein glue, or other known forms of adhesive lcommonly used in the carton art. When the surface of the panel II with wllich'the adhesive comes into contact is a surface having a paramne in the trade as-a exible glue, as distinguished from a hard glue or glue which will crystallize. The adhesive is usually applied by the cartonmaking machinery to the under surface of the nap I l, as shown in Fig. 1, and then when the blank is folded overfrom the position shown in l'lg. 1 to the position shown in Fig. 2, this zone or line of adhesive will come down onto the' upper surface of the panel Il near the top edge thereof,

` desired for any reason to coat the carton maandaecure the parts Il and il to-each other.

Ifthe flap libesecuredtothe panel Il with a uniform degree of intensity of adhesion throughout the entire length of the adhesive sone, then a pull on the tab ii in a direction erosswise of this-adhesive zone is very apt to cause the flap Il to tear along lines extending inwardly (vertically when viewed as in Figs. l and 2) at approximately the side edges or corners of the tab Il. -This is particularly true when the grain Iof the carton board runs vertically or around the periphery of the carton. Buch tearing inwardly at the sides of the tab appears to be due to the fact that when the tab is pulled, there is initially `a greater intensity of stress produced in the flap Ii atvthe sides of the tab, than at the other points along the ap il more remote from the tab.

To avoid such'telml, it is desirable to reduce me intensity of the adhesive connection or bond between the layers II and ill at points adjacent the sides or corners of the tab I0. When the adhesive bond at these points is thus reduced.

the resistance to the pulling back of the tab is lessened at these points where the greatest stress occurs so that tears are not likely to start at these points. At other points, where the intensity of the adhesive connection is not thus reduced. the intensity or concentration ofthe stress is less., so that there is little or no danger .of tearing.

In order thus tov reduce the intensity or strength of the adhesive bond at the desired points, one or the other of `the two overlapped layers of sheet material is preferably provided with a coating to weaken the adhesive bond. IIy'his may be accomplished by the use of a coating of material which has a less affinity for the adhesive than the carton material. Or, if it is terial throughout substantially the entire area of the adhesive with a material having a reduced affinity for adhesive, then a thicker or heavier coating of the same material or a coating of a different affinity-reducing material is employed at the dedred points (near the sides of the tab II) to produce the effect above mentioned.

So far as the prevention of tearing inwardly from the sides or corners of the tab is concerned, the amnlty-reducing or bond-weakening coating may be applied either to the layer Il or to the layer il. It is preferred, however, to apply this coating to the layer il, and to arrange it in auch a way that it not only serves to prevent tearing at the tab corners, but also assists in coniining surface tearing of the sheet material to the v layer Il, reducing or eliminating surface tearing of the layer il.

aisaosc 1n the embodiment here shown, the bondweakening or aflinlty-reducing coating is applied to the `outer surface of the inner layer il in the.

form of a strip I8 having relatively narrow portions throughout the major part of its length overlapping a small part only of the width of the adhesive zone l1, and having enlargements or wider portions I9 adjacent the sides. or corners of the tab I6, which wider portions I9 extend throughout substantially the entire width of the adhesive zone l-'I when the parts are in the completed position shown in Fig. 2. This coating Il thus reduces the adhesive bond to some slight extent throughout substantially .the entire length of the adhesive zone, but reduces it especially and to a greater extent at points approximately opposite the'sides or corners of the tab II, where thel greatest stress occurs in pulling the tab to open the carton, and where the greatest likelihoodof tearing occurs.

Since the coating I8 extends throughout substantiallyl the entire length of the adhesive zone i1 at the outer edge of such zone (that is, at the lower edge when viewed as in Fig. 2, or the edge closest to the extreme edge of the flap i5) it follows that asthe ilap il is pulled upwardly away 'ing'on the flap i5 is highly desirable, because it eliminates any surface tearing of the fibrous material of the layer II. As pulling is continued, the body of adhesive I1 will tend to remain firmly attached to the flap I5, producing no surface tearing of this flap, and will tend to break away from the layer Il as the breaking of the joint proceeds past the edge of the coating Il.

\ 'Ihus such surface tearing v-of the bers as is produced will be produced in the layer Il rather than in the layer I5 and will be confined to the relatively narrow area between the coating Il and the extreme end or edge of the layer Il, since the tearing will necessarily stop when the extreme edge of the sheet is reached.

` 'The 'coating Il may be of any suitable material which has the desired lessened aillnity for the particular glue or other adhesive which is used. A layer of paramn has been found quite satisfactory in many instances for forming the coating Il. It is preferred. however, to use an ink of a type which tends to repel the adhesive and has a relatively small afllnity for the adhesive. Satisfactory inks for this purpose are printing or lithographing inks with a base of oil or wax, or a combination of oil and wax. Printing or lithographing inks with an aniliney base are also satisfactory in some instances. The coating il when in the form of ink, can be applied very quickly to the carton wall Il by a simple printing operation.

A modified form of construction is illustrated in Figs. 4 and 5. Here, thexmain difference is that the adhesive.l instead of being applied in the form of 'a continuous strip Il, is applied in the form of a discontinuous line or zone. of adhesive, such as a series of spaced spots 2l. The diamond-shaped spots here illustrated are -par-7 ticularly eiilcient, because the lower points of the diamonds present only a slight resistance at the beginning of the pulling apart or separating operation, which resistance increases as the pullingproceeds. Thusitiseasytostarttheseparation or breaking oi the joint by a slight torce, and once the breaking is started, it continues easily with the continuous application oi reasonable force. y

Except for the use oi' a zone or line of spaced spots of adhesive in place of4 a continuous strip of adhesive, the construction shown in Figs. 4 and 5 may otherwise be identical with the construction illustrated in Figs. 1 to 3, and the same parts are indicated by the same reference numerals. A It desired, the aiiinity-reducing or bondweakening coating may comprise two or more layers of the same or diflerentmaterial, superimposed upon each other. For instance, the modification illustrated in Fig. 6 comprises a coating 28 oi the same shape' previously disclosed in connection with the coating I8, and having a wider portion 29 corresponding to the wider portion I9 previously disclosed. This coating may be of adhesive repelling ink as above mentioned. The carton is also provided with an overlapping coating 38, oi the same material, and of a width sufficient to cover the entire width of the adhesive zone. Either of these two coatings may be applied ilrst. With this arrangement, the bond between the adhesive and the iibrous layer to which the coatings are applied will be weakened to some extent throughout theentire area of the adhesive (thus conilningsurface tearing of the sheet material to this layer rather than to the other layer of sheet material), and will be weakened to an eren greater extent where the bond-reducing coating is oi double thickness, at the portions 28 and 29 (thus preventing tearing back at the sides or corners of the tab I6) 'Ihis arrangement of using two superimposed iayers of adhesive-repelling or bond-reducing material is not confined, of course, to the use of ink as the bond-reducing material. Fig. '7 is intended to illustrate a similar arrangement in which both layers are of parain, one coating at 38 with the enlargement 39 corresponding in shape to the previously described coatings I8, I9, 28, and 29, and the other coating being indicated at 48. lThroughout the area of the coating 38, 39, the

paraiiin will be of double thickness, and the adhesive bond will be greatly reduced in the manner previously explained in connection with Fig. 6. Where the adhesive comes in contact only with the coating 48 and not with the coating 38, 39, the bond will also be reduced but to a lesser extent, and this reduction of the bond will be suiiicient to confine surface tearing of the sheet material to the layer to which these coatings are applied (preferably the layer I I), preventing such surface tearing from occurring in the other layer.

Another modification is illustrated in Fig. 8. Here there is provided a coating 48, with an enlargement 49, corresponding in shape and arrangement to the coatings I8and lpreviously described, this coating 48, 49 being of ink. A coating 58 of parafn is also employed, in the manner above mentioned in connection with the coatings 88 and 48. It is immaterial Whether the.

paraiiin coating or the ink coating be applied ilrst, but it is usually desirable to apply the ink iirst and then the` parafiin, as shown in Fig. 9. Since both the parafn and the ink have the eect of repelling the adhesive or reducing the adhesive bond, it follows that throughout the area of the ink coating, where both the paraiiin and the ink are present, the bond will be greatly reduced, and outside oi' the area of the ink coating, where only the parafiln coating is pres'- ent, the adhesive bond will also be reduced, but to a lesser extent.

In the modincation illustrated in Pig. l0, a

bond-reducing coating (which may be leither ofy ink, or of paramn, or of any other suitable material having the desired eiiect) is employed in a somewhat different form or shape.v Here, the

coating is in the form oi two or more narrow' strips or lines 88. Between these strips or lines, the adhesive will contact with the sheet material oi' which they carton is made and have its full adhesive power or bond, but along these coating lines 85 the bond will be reduced enough so that the adhesive will tend to remain attached to the other layer of sheet material and tend to break away from ythis layer to which the coatings 55 are attached. Surface tearing of the material is thus conned to this coated layer, where the tearing can proceed no further'than the closely adjacent edge of the material, and tearing is avoided in. the ilap I5, where such surface tearing could proceed lan indefinite distance, into the vpanel I4 or perhaps even further.

. not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention or the scope of the appended claims. i

I claim:

1. A carton comprising two overlapping layers of brous sheet material, adhesive means connecting said two layers to each other, one of said layers being adapted to be pulled away from the. other layer to break the adhesive connection between them by a pull exerted on said one oi' said layers adjacent said adhesive means, said one of said layers during such pulling being subjected, in a portion adjacent the point where the pulling force is applied, to stress of high intensity relatively to the stress produced in other portions of `said one layer, and means for reducing the strength oi' theadhesive bond between said two layers at said portion of relatively` high stress.

2. A carton comprising two overlapping layers of iibrous sheet material, adhesive means connecting said two layers to each other, one of said layers being adapted to be pulled away from the other layer to break the adhesive connection between them by a pull exerted on said one of said layers adjacent said adhesive means, said one of said layers during such pulling being subjected, ina portion adjacent the point where the pulling force is applied, to stress oi high intensityrelatively to the stress produced in other portions of said one layer, and means for rendering the adhesive bond between said two layers weaker at said portion of relatively high stress than at ly along a zone, tab means on one of said layers to be grasped to pull said layer away from the other oi said layers to breakthe adhesive connection between them, said one nf said layers being subjected, during the pulling operation, to stress Aoi.' relatively high intensity adjacent one side of said tab means, and means for reducing the intensity of the adhesive connection between said two layers at a point on said zone approximately in line with said side of said tab means.

5. A carton comprising two overlapping layers of fibrous sheet material, a zone of adhesive connecting said two layers to each other, one of said' layers having a portion which may be conveniently grasped to pull said one of said layers away from the otherof said layers to break the adhesive connection, and a coating on one of said layers having less ailinity for said adhesive than said sheet material, said coating extending across a greater part of saidzone of adhesive at a point adjacent said means to be grasped than at other points of said zone.

6. A carton comprising an inner layer and an outer layer of fibrous sheet material overlapped with each other. a zone of adhesive connecting said two layers to each other, tab means on said outer layer to be conveniently grasped to pull said outer layer away from said inner layer to break the adhesive connection between them, and a coating of material on the outer surface of said inner layer to reduce the amnity of the coated 7. A carton comprising an inner layer and an outer layer of brous sheet material overlapped with each other, tab means on said outer layer to be grasped to pull said layers apart, a zone of adhesive applied to the inner surface of the outer layer for contact with the outer surface of the inner layer to secure said two layers to each other, and a 'coating on the outer surface of the inner layer of material reducing the adhesion between said adhesive and said inner layer, said coating extending along' said zone of adhesive and having a less width than the full width of said zone throughout the major portion of the length of said zone, and being substantially wider at points on said zone approximately in alinement with the sides of said tab means, to reduce the adhesive connection between said two layers in line with the sides of said tab means, and to reduce the possibility of said outer .layer tearing when force is applied to said tab means.

8. A carton comprising an` inner layer and an outer layer of brous sheet material overlapped strength of the bondbetween said adhesive and said inner layer below the strength of the bond between said adhesive and said outer layer, so that when said two layers are pulled apart, the adhesive willbe more likely .to pull away from A the inner layer than from the outer layer and so that any surface tearing of the sheet mate will occur mainly in the inner layer.

9. A cartonv comprising an inner layer and an outer layer of fibrous sheet material overlapped with each other, said outer layer having a portion to be grasped to pull said outer layer away from said inner layer, a series of spaced spots of adhesive connecting said two layers to each other, and a coating of adhesive repellent material on the outer surface of the inner layer throughout at least a part of the area of said spots of adhesive, to reduce the strength of the bond between said adhesive and said inner layer below the strength of the bond between said adhesive and said outer layer, so that when said two layers are pulled apart, the adhesive will be more likely to pull away from the inner layer than from the outer layer and so that any sur face tearing of the sheet material will occur mainly in the inner layer.

l0. A carton comprising two overlapped layers of iibrous sheet material, means on one of said layers to be grasped to pull said one of said layers away from the other of said layers, a zone of spaced spots of adhesive connecting said two layers to each other, anda coating of adhesive repellent material on one of said layers extending along said one of said layers adjacent said zone of adhesive and having a width extending substantially across the full width of said zone of adhesive adjacent the sides of said means to be grasped and having asubstantialiy lesser width along the rest of said zone of adhesive.

l1. A carton of the type wherein two overlapping layers of sheet material are adhesively connected to each other and are adapted to be pulled away from each other to break the adhesive connection betwen them by a pulling force applied to one layer and producing a higher intensity `of stress in that layer adjacent the point where the force is applied than at other points more remote therefrom, characterized by means for rendering the adhesive bond between said two layers weaker at said point of high intensity stress than at said other more remote points.

HARRISON C. BLOOMER. 

